Edwin chapman



@atten gistenA @strut @Hirn EDWIN CHAPMAN, I OE ROCHESTER, MINNESOTA.

Letters Patent No. 70,802, dated November 12, 1867. I

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TO ALL WHOM IT MAY CONCERN:

Y Be it known that I, EDWIN CHAPMAN, of Rochester, in the county of Olmsted, and State ofMinnesota, nave invented a new and useful Improvement in Rotary Steam Engines; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable those skilled inl the art to make and use the same, reference being had tothe accompanying drawings, forming part of this specication.

This invention relates to certain useful improvements in the class of steam engines known as rotary engines, and kit consists principally in the manner in which the abntments are operated, and in the manner in which the steam is dischargcd into the cylinder and exhausted therefrom.

Figure 1 is a vertical section of the engine, through the line x :v of g. 3.

Figure 2 is a-vertical section of iig. I, through the line y y.

Figure 3 is a. top or plan view of the engine.

Figure 4 is a section through the line z z of tig. 1.

Similar letters of reference indicate corresponding parts.

This engine is attached to a frame, which sets on and is secured to a bed-plate. A represents the bedplate. B is the frame, which is rais-ed above the bedplate,'und rests on pillars a. C is the cylinder, which is formed of two parts or half cylinders, in `which works the piston D. E is the engine shaft. F isthe steam pipe, vwhich is connected with the boiler. The steain enters the-cylinder through the face of the piston at c, as seen in fig. 2. The piston is attached to a disk-plate, d, which is securely fastened to the shaft E, and is connected with the steam pipe F by achamber which is made inthe eye of the cylinder marked c. f, fig. 1,is.an aperture from the cylinder to the centre of the shaft, which shaft is made hollow, as seen in fig. 2, for the exhaust of thea steam. The chamber e is always under a. pressure of steam, with anV aperture, g, connecting it with the piston,

so that whenever the pistou passes' theiaperture j, `the piston takes steam, or rather discharges steam through the aperture lc against the abutments h t. The cylinder 1s slotted on each side, as seen in iig. 1, so that these abutments can playin and out. These abutments are attached to vertical shafts it', which shafts lare supported by wings J J, which project fro'm each side of the cylinder. These wings are formed of two plates, each having recesses between them, intowhich the abutmcnts are thrown when they are turned from the cylinder. The

shafts i are packed by stuffing-boxes, z", on each side of the wings, as seen in the drawing.

The manner in which these abutments are operated, so that they shall receive the full pressure of steam, and recede from the cylinder to allow the piston to pass at every revolution, is as follows.: AIn the shaft atl'k there is an eccentric groove. m m and m m are arms, which are attached to vertical shaftso. n n, are brackets, hy which the top ends of the shafts o are supported. There are pins on the ends of the arms m `which work in the eccentric groove c, so that as the shaft revolves the upright shafts o are partially revolved` or given a vibratory motion. To communicate this vibrating motion to the shafts z', and thus operate the abutments h, there are other arms von the shafts 0 marked m. p p are rods, which connect the arms m with the shafts'iby short cranks or arms o. The motion thus imparted to the abutments is suiicient to throw them entirely from theA cylinder', as well as into it, atevery revolution of the shaft Outside of tho chamber there are small packing-rings, seen at r. These ringsiare tapering or wedge-shaped, and are cut like ordinary"pa.cking rings in one or more places. As the surfaces wear, the spring of the'ring, in its tapering seat, will force it out so that it will always insure a tight joint. Around the shaft E there are also packing-rings, S S, which are eut in one place, and spring into a recess, as seen in the drawing, for the purpose of insuring a tightjoint between the shaft and the central portion or eye of the cylinder. The aperturef in the revolving disk-plate of the piston, being brought in communication with the hollow shaft twice in each revolution, the steam is exhausted thereby from the end of the shaft E.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

l. The arrangement of the steam-chamber e, aperture g, and packing r, with reference to the piston D .and shaft E, as heroin described, for the purpose specified.

2. The construction of the piston D, provided with the opening for discharging steamintoy the cylinder, and opening f, for exhausting the steam through the shaft, substantially as herein shown and described.

The above specification of my invention signed by me this 28th day otMay, 1867.

EDWIN CHAPMAN. Witnesses:

WM. F. McNAMAnA, ALEX. F. Ronnn'rs. 

